Bernanke Hits Back at Critics of Bond-buying Plan

WASHINGTON (AP) — Federal Reserve Chairman Ben Bernanke is seeking to defuse rising criticism of the Fed's $600 billion bond-purchase plan by arguing that it's needed to bolster the economy and reduce unemployment. But he warns the Fed's program can't succeed on its own.

The Fed chief makes his most forceful case to date that Congress also must provide more stimulus aid. Without it, he says high unemployment could persist for years. In making that argument, Bernanke risks heightening complaints that he's plunging the Fed into partisan politics.

He also says the global economy could falter if struggling countries abroad don't receive sufficient support.

Bernanke makes the remarks in a speech prepared for delivery to a banking conference Friday in Frankfurt, Germany. A copy of his speech was made available Thursday night.